Found 565 results
Open Access
Article
01 December 2025Preparation, Characterization and Performance Assessment of Metal Complexes of Curcuma longa Extract as Sensitizers for Dye-Sensitized Solar Cells
The dye extract of Curcuma longa (turmeric), which is very rich in curcumin, was chemically modified by complexation reaction with Zn2+, Cu2+, and Fe3+ ions to enhance its stability, electron transfer and photovoltaic performance. The dye and complexes were characterized by Ultraviolet-Visible (UV-Vis) absorption and Fourier Transform Infra-Red (FTIR) spectroscopy of potential chromophores and functional groups. The spectral data obtained indicated that the curcuminoid ligands were successfully coordinated with the metal centers, resulting in red-shifted absorption bands from beyond 460 nm and C=O vibrational frequency decreasing below 1650 cm−1. Complexation reaction resulted in improved photochemical response and enhanced light-harvesting potential. When compared, the solar cells fabricated with titanium dioxide (TiO2) photoanodes sensitized by the complexes afforded improvement in the magnitude of short-circuit current density as well as power conversion efficiency compared to the devices sensitized with the crude extract. Among the three complexes, the Zn-complex afforded the highest efficiency (1.20%), attributed to favourable electronic coupling and reduced recombination losses. Computational studies conducted through quantum chemical calculations based on the curcumin structure supported the experimental findings. The findings from this study demonstrate that metal ions-natural dye complexes have potential for application as low-cost, eco-friendly and sustainable sensitizers, thereby opening a novel horizon in green photovoltaic technologies.
Open Access
Article
28 November 2025Sustainable Bioplastic Using Lignin Extracted from Neolamarckia cadamba Bark by Deep Eutectic Solvent
Lignin, a highly complex and abundant biopolymer, forms an integral part of plant cell walls and represents a promising resource for sustainable industrial applications. Lignin has recently gained attention due to its potential use in biofuels, bioplastics, adhesives, and antioxidant formulations. This paper focuses on lignin extraction from Neolamarckia cadamba bark by deep eutectic solvent (DES) composed of thymol and menthol. Extracted lignin and starch (extracted from Colocasia esculenta roots) were used for the synthesis of bioplastic. The extracted lignin was characterized through multiple analytical techniques, including UV-V is spectroscopy, FTIR, and visual staining with safranin. Bioplastic was characterized for thermal resistance, absorbance, and solubility. The moisture content was obtained as 29.59%, water solubility as 72.61% with almost completely (98%) biodegradable. The work contributes to valorising environmental biomass and enhancing the industrial relevance of lignin. Furthermore, it aligns with the sustainable development goals by transforming bio-waste into valuable bioproducts, such as bioplastics, biochemicals, bioadsorbents, etc. The outcomes of this research may serve as a foundation for future studies in lignin-based material innovation and biorefinery integration.
Open Access
Article
28 November 2025Binocular Camera-Based Depth Recognition for Motion Monitoring and Response Analysis of Flexible Floating Structures for Offshore Photovoltaics
Driven by the global goal of carbon neutrality, offshore floating photovoltaic (OFPV) technology has become a primary focus of photovoltaic research. In particular, flexible thin-film structures have become a central focus of research in sustainable energy development. It offers numerous advantages, including light weight, low cost, and strong adaptability to the marine environment. However, traditional experimental methods still face challenges in accurately capturing the motion response of flexible thin films. To address this issue, this study proposes a motion measurement and monitoring framework based on binocular vision. The framework is validated using gyroscope data, and the results demonstrate its high accuracy and real-time performance. The research team conducted experiments on a flexible floating photovoltaic structure in a wave flume, applying the proposed framework to monitor its motion response under wave excitation. The experimental results show that wave height and wave period have significant effects on the acceleration response of the thin film: higher wave heights lead to notably greater accelerations, whereas longer wave periods result in a gradual decrease in acceleration. Overall, the proposed framework provides reliable technical support for the design optimization and safety assessment of flexible thin-film FPV structures.
Open Access
Article
27 November 2025The Limits of RGB-Based Vegetation Indexes under Canopy Degradation: Insights from UAV Monitoring of Harvested Cereal Fields
Unmanned Aerial Vehicles (UAVs) equipped with RGB cameras are increasingly used as low-cost tools for crop monitoring, offering a range of vegetation indexes in the visible spectral range. These indexes have often been reported to correlate with other multispectral indexes such as the Normalized Difference Vegetation Index (NDVI) during active growth stages. However, still efforts should be done about their performance under conditions of canopy degradation. In this study, UAV flights were conducted over a cereal field immediately after harvest, when the canopy consisted mostly of bare soil and dry residues. RGB-based indexes were calculated from the orthomosaic, normalized to a [0–1] scale, and compared to NDVI derived from a multispectral sensor. Data preprocessing included ground control point (GCP) georeferencing, removal of NoData pixels, and raster alignment. Results revealed very weak correlations between RGB indexes and NDVI (Pearson r < 0.15), with Visible Atmospherically Resistant Index (VARI) showing almost no variability across the field. Although the Leaf Index (GLI), yielded the lowest error values, all RGB indexes failed to reproduce the variability of NDVI under post-harvest conditions. These findings highlight a critical methodological limitation: RGB indexes are unsuitable for vegetation monitoring when canopy cover is severely reduced. While they remain useful during active growth, their reliability diminishes in degraded or post-harvest scenarios, thereby limiting their application in assessing abiotic stress in cereals.
Open Access
Article
27 November 2025Lyz1-Expressing Alveolar Type II Cells Contribute to Lung Regeneration
The alveolar units, composed of alveolar epithelial type II cells (AT2) and type I cells (AT1), are essential for efficient gas exchange. While AT2 cells are known to play critical roles in alveolar homeostasis and regeneration, the contribution of heterogeneous AT2 cells to lung repair remains poorly understood. Here, we identified a distinct AT2 subpopulation that exclusively expressed Lysozyme 1 (Lyz1) through single-cell RNA sequencing (scRNA-seq) analyses. Cell fate mapping revealed that the Lyz1CreERT2 mouse strain specifically labeled Lyz1-expressing AT2 cells in vivo at homeostasis. Following lung injury, Lyz1+ AT2 cells expanded and contributed to alveolar regeneration by generating both self-renewing AT2 cells and differentiating AT1 cells. We further observed the emergence of de novo Lyz1-expressing cells in the airways after lung injury. Additionally, Lyz1+ AT2 cells displayed significantly enhanced proliferative capacity compared with general bulk AT2 cells in 3D organoid cultures. These findings define Lyz1+ AT2 cells as a previously unrecognized progenitor population, expanding the paradigm of alveolar regeneration and providing insight into how epithelial diversity supports lung regeneration.
Open Access
Article
25 November 2025The Impact of Digital Infrastructure on Economic Resilience: Evidence from the Four Major Regions of China
Amid accelerating global structural changes and China’s transition to the digital-driven fourth industrial revolution, this paper examines the impact of digital infrastructure on economic resilience by clustering China’s 31 provinces into the four major economic regions during 2008–2022. Through the application of the Threshold Regression Model, Mediation Effect Model, and GTWR Model, the analysis reveals that digital infrastructure exhibits a threshold effect in enhancing economic resilience, with significant increasing marginal returns beyond specific scale thresholds. Regional heterogeneity is pronounced: the eastern region demonstrates amplified nonlinear benefits, while the northeast exhibits diminishing returns after crossing the threshold. Industrial diversification is an effective way for digital infrastructure to build resilience. The effects of industrial specialization, however, vary by region: it strengthens resilience in the east, weakens it in the central region, and shows no statistically significant impact in the western and northeastern regions. The findings provide empirical evidence for regionalized policymaking during technological paradigm shifts, highlighting the need to consider both digital infrastructure scale thresholds and industrial structure dynamics in economic resilience strategies.
Open Access
Review
20 November 2025Vibrational Spectroscopy in Forensic Science: A New Frontier for Biopharmaceutical Drug Authentication
The global proliferation of counterfeit biologic medicines poses a growing threat to public health and pharmaceutical integrity. Traditional laboratory-based methods for verifying drug authenticity are often time-consuming, costly, and impractical for real-time or field-based applications. This paper explores the emerging potential of infrared (IR) and Raman spectroscopy for forensic detection and authentication of biologics. While these technologies are currently underutilised in forensic science, advancements in instrumentation and data analysis are rapidly enhancing their sensitivity, portability, and usability. Focusing on protein- and peptide-based therapeutics, the paper reviews the principles and applications of IR and Raman spectroscopy, highlighting their ability to detect structural and compositional differences between authentic and counterfeit biologic drugs. The discussion emphasises the importance of interdisciplinary collaboration between forensic and biopharmaceutical sciences. As counterfeiters become more sophisticated, the integration of non-destructive spectroscopic tools into forensic workflows offers a promising path toward the rapid and reliable screening of biologic drugs in both field and laboratory settings.
Open Access
Article
19 November 2025Effects of Platform Motions on Dynamic Responses in a Floating Offshore Wind Turbine Blade
Floating offshore wind turbines (FOWTs) offer great potential for harnessing deep-sea wind energy. This study examines the effects of six-degree-of-freedom (6-DOF) platform motions on the dynamic structural responses of a FOWT blade by comparing its performance with a fixed-bottom system. Integrated aero-hydro-servo-elastic simulations for a 5-MW spar-type FOWT were conducted under various design load cases. Results indicate that the floating tower’s first-order natural frequency was about 29% higher than that of the fixed-bottom tower. Platform motions markedly influenced blade flapwise and torsional responses, with the effect intensifying under larger waves. For instance, as the significant wave height increased from 1.70 m to 9.90 m, the differences in peak response between the floating and fixed-bottom systems grew from 0.104 m to 0.363 m for blade-tip flapwise deflection, from 528.1 kN·m to 1817.4 kN·m for the root flapwise bending moment, and from 5.02 kN·m to 18.73 kN·m for the root torsional moment. In contrast, blade edgewise responses showed negligible changes, with peak deflection differences below 0.05 m. Blade loads were more sensitive to wave conditions, while platform motion magnitudes were more affected by wind. These findings offer insights into the load characteristics and structural design of FOWT blades.
Open Access
Article
19 November 2025Hydrogenative Depolymerization of Polyesters Catalyzed by a PN3-Ruthenium Complex Using Both H2 and EtOH as Hydrogen Sources
Selective hydrogenative depolymerization of polyesters to diols is regarded as a promising strategy for plastics upcycling. However, many catalysts documented in literature still involve harsh reaction conditions, such as high temperature and high H2 pressure. In this work, we present a PN3-ruthenium complex catalyzed polyesters upcycling into various highly value-added diols under mild reaction conditions using H2 as a hydrogen source. It is worth noting that PLA depolymerizes into 1,2-propanediol under 1 MPa hydrogen pressure at ambient temperature within 2 h; the conditions are much milder than those of previous reports. Aromatic polyester PET degradation needs harsher reaction conditions (80 °C, 4 MPa, 3 h). The different reaction conditions enable direct separation of the degradation products of PLA and PET mixture via sequential depolymerization, as well as mixing them with polyolefins (PE, PP, PS). More strikingly, this catalyst is also effective for the catalytic hydrogenation of polyesters in the presence of ethanol to afford various diols, avoiding the use of harsh reaction conditions and an expensive autoclave.
Open Access
Article
18 November 2025Turbulent Characteristics in an Egg-Shaped Orifice Fishway and a Comparison with a Rectangular Orifice
A fishway can assist fish species in overcoming barriers to migration, which depends on the eco-hydraulic characteristics of the fishway. Based on the tail fish benefiting when at the rear of a school than when at the front, and taking into account most anadromous fish species being characterized by egg-shaped morphology, the turbulent characteristics of an egg-shaped orifice fishway were experimentally studied in a fishway flume, a comparison with a rectangular orifice fishway with the same aspect ratio was made. The results showed that the maximum longitudinal velocity for the egg-shaped orifice decays faster than that for the rectangular one, the longitudinal velocity profile exhibits two peak values, while the corresponding velocity distribution for the rectangular orifice only reveals one peak, peak values of turbulence intensity on the different horizontal plane of egg-shaped orifice occur in the orifice edges, the larger turbulence intensities still exists in the central besides the edges for the rectangular orifice, Reynolds stress reaches peak value at the orifice edges, Auto-correlation coefficient of longitudinal velocity within orifice region is of small amplitude and short period relative to the outside the orifice region, microscale eddies within the orifice region were larger than those outside, mean scale of eddy is of larger variation and shorter period, and develops outside the orifice region, frequency-spectrum of velocity fluctuation exhibits dominant frequency in the low-frequency domain.
